A=orrsommerfeld_demo(1000);n=999;
xmin=-.5;
xmax=0.1;
ixmin=-1;
ixmax=0;

% ov=3;
% 
% [x,ix,si]=ps1(A,xmin,xmax,ixmin,ixmax,ov);

ov=20;
[x,ix,si]=xpseudospectrum(A,xmin,xmax,ixmin,ixmax,ov);


hold on
hidden on
xlim([-.5 .1])
ylim([-1 0])
zlim([0 10])
surfc(x,ix,si,'EdgeColor','none');
xlabel('real');
ylabel('imag');
e=eig(A);
plot3(real(e),imag(e),0*ones(n,1),'+r');
hidden off
hold off
